Method of preparing the ends of cables for splicing

ABSTRACT

To prepare a multi-conductor jacketed cable for splicing it is necessary to remove the jacket for some distance from the end of the cable and to cut the conductors so that they extend for different distances from the end of the jacket. This is done by first gripping the cable by a clamp some distance from its end. Longitudinally spaced pairs of cutters are then brought together to cut through the conductors and through the jacket to the conductors with the cut through the jackets being spaced toward the clamp from the end of the cable a greater distance than the cut through the conductors. The clamp is then moved away from the cutters so as to pull the main portion of the cable with it while leaving the portions of the jacket and conductors between the cutters and the end of the cable behind.

United States Patent Abarotin [4 Jan. 7, 1975 METHOD OF PREPARING THEENDS 0F 3,706,241 12/1972 Balmer et al. 81/951 CABLES O SPLICING3,768,143 10/1973 Holmes 81/951 3,774,478 11/1973 Carpenter et a1 81/951Eugene V. Abarotin, Franklin Township, Westmoreland County, Pa.

United States Steel Corporation, Pittsburgh, Pa.

Filed: Oct. 3, 1973 Appl. No.: 403,229

Related US. Application Data Division of Ser. No. 243,331, April 12,1972, Pat. No. 3,786,697.

Inventor:

Assignee:

US. Cl 29/427, 29/203 R, 29/628, 29/629 Int. Cl B23p 19/02 Field ofSearch 81/9.5 R, 9.5 A, 9.51; 30/901, 90.6, 90.7, 90.8, 91.2; 29/628,203

R, 200 R, 200 D, 427

References Cited UNITED STATES PATENTS Way 30/908 Primary Examiner-C. W.Lanham Assistant Examiner-James R. Duzan Attorney, Agent, or FirmWalterP. Wood [57] ABSTRACT To prepare a multi-conductor jacketed cable forsplicing it is necessary to remove the jacket for some distance from theend of the cable and to cut the conductors so that they extend fordifferent distances from the end of the jacket. This is done by firstgripping the cable by a clamp some distance from its end. Longitudinallyspaced pairs of cutters are then brought to 1 Claim, 10 Drawing Figures5 Sheets-Sheet 1 A YM Patented Jan. 7, 1975 3, 3,302

5 Sheets-Sheet 2 Patentfl Jan. 7, 1975 5 Sheets-Sheet 5 FIG. 3

Patented Jan. 7, 1975 5 Sheets-Sheet 4 F/G 7 Fla. 8

Patented Jan. 7, 1975 3,858,302

5 Sheets-Sheet METHOD OF PREPARING THE ENDS OF CABLES FOR SPLICING Thisis a division of application Ser. No. 243,331, filed Apr. 12, 1972, nowUS. Pat. No. 3,786,697.

This invention relates to a method of preparing the ends ofmulti-conductor jacketed conductors for splicing and more particularlyto mine cables having two conductors and a ground lead. The cablesplicing is generally required to increase its length or because ofdamage to its insulation, conductors or ground leads. Before theconductors can be joined, a part of the cable jacket must be removed,the conductors and ground leads cut to proper lengths, and theinsulation removed from the ends of the conductors. Two conductor endswith the same polarity are then inserted into a copper sleeve from theopposite ends and the ends of this sleeve are crimped, thus joining thepreviously severed conductors. By insulating the conductors from eachother and from the ground lead, and putting a jacketing material aroundthem all, the splice is completed.

Usually the jacket has been removed by means of a penknife and theconductors have been cut with pliers. Stripping with a penknife is verydifficult and often results in damaging the conductor insulation. Thisdamage may remain unnoticed and may result in a short circuit. Theconductors, after crimping, must be of the same length since otherwisethe short conductor will take the total tension applied to the cable andmay break. It is very difficult to cut the conductors with hand tools toobtain this equal length.

An object of the present invention is to provide a method of cutting theconductors of a jacketed multiconductor cable to predetermined lengthsand at the same time removing the jacket from a predetermined portion ofthe cable without damaging the conductor insulation.

This and other objects will be more apparent after referring to thefollowing specification and attached drawings, in which:

FIG. 1 is a side elevation of the apparatus for practicing my invention;

FIG. 2 is a top plan view of FIG. 1;

FIG. 3 is a view taken on the line III--III of FIG. 1;

FIG. 4 is a view taken on the line lVIV of FIG. 2 with parts removed soas to show only the die block;

FIG. 5 is a sectional view of a cable to be prepared;

FIG. 6 is a perspective view of a prepared cable;

FIG. 7 is a view of the ground cutting blade;

FIG. 8 is a view of a cutting blade;

FIG. 9 is a view taken on the line IX-IX of FIG. 2; and

FIG. 10 is a view taken on the line XX of FIG. 2.

Referring more particularly to the drawings, refer ence numeral 2indicates a table top for supporting step cutter 4 and cable stripper 6of my invention. Step cutter 4 includes a base plate 8 attached by meansof bolts 10 to table top 2. Transversely spaced apart vertical plates12, welded to plate 8, have aligned openings 14 therethrough. The top ofeach plate 12 has spaced lugs 16 extending upwardly with alignedcircular holes 18 therethrough. A cover plate 20 has similar lugs 22 oneach end which are received between lugs 16. Holes 24 in lugs 22 arealigned with the holes 18 so as to receive pins 26 and 28. Pin 26 servesas a pivot for the cover plate 20 while pin 28 has a transverse pin 30attached to one end so as to facilitate its removal when it is desiredto swing the cover plate 20 into inoperative position. The foregoingforms a housing 31.

As best shown in FIG. 3 a fluid cylinder 32 extends upwardly through andis threaded into a hole in plate 8. A piston rod 34 mounted in cylinder32 has a pressure plate 36 secured to its upper end above plate 8.

A step cutter die block 38 is mounted on plate 36 in housing 31 betweenplates 12. The die block 38 in eludes bottom blade plate 40, top bladeplate 42, and intermediate guide plates 44 mounted on four vertical rods46. Plate 42 is secured to each rod 46 between shoulder 48 and washer 50by means of capscrew 52 threaded into the top of the rod. Downwardmovement of plate 40 is limited by means of washers 54 held in place bymeans of capscrews 56 threaded into rods 46. Plates 44 are heldassembled together so that they can be considered a single plate. Twosprings 58 surround each rod 46, one bearing against the top of plate 40and the bottom of lower intermediate plate 44 and the other bearingagainst the top intermediate plate 44 and the bottom of plate 42. Setsof spring 58 and spring 60 are similarly positioned in four locationsbetween the rods 46. The springs 58 and 60 are precompressed at assemblyto support plates 44 with its cable guide opening 62 centered betweenplates 40 and 42 as best shown in FIGS. 3 and 4.

One type of cable C with which my device may be used includes arectangular ground wire G, two conductor strands S, each surrounded by aplastic insulator P, and a rubberjacket J. For this cable the opening 62will be shaped as shown. The remaining parts of the die block 38 willalso be described with reference to this cable.

As best shown in FIG. 9 the bottom plate 40 supports a notching blade64, a ground cutting blade 66, and two conductor cutting blades 68. Inlike manner the top plate 42 supports a notching blade 64, a groundcutting blade 66, and two conductor cutting blades 68 which arepositioned to cooperate with the corresponding blades in the bottomplate. It will be seen that each blade 64 has a curved cutting surface648 (FIG. 4) of less width than the width of cable C, but of slightlygreater width than the distance between the outside of insulatedconductors S so that the jacket J will be cut but the conductors andtheir insulation will not be cut. Each blade 66 has a cutting surface66S (FIG. 7) of such dimension that the blades 66 will cut throughground G without cutting conductors S or their insulation. Each blade 68has a cutting surface 68S (FIG. 8) of such dimension that each set ofblades 68 will cut through one of the conductors S without cuttingground G or the other conductor S. The spacing, configuration and sizeof the blades depends upon the size and construction of the cable.Hydraulic fluid is preferably provided for cylinders 32 and 83 by meansof a manually operated pump (not shown).

The cable stripper 6 is positioned adjacent the end of step cutter 4having the notching blades 64. The stripper 6 includes a base 70 formedof two end plates 72 and 74 connected by and welded to side plates 76.Plate 72 has a horizontal flange 78 secured thereto which rests on plate8 and is secured thereto by means of capscrews 80. A horizontal fluidcylinder 83 is positioned within base 70 and secured thereto by means ofplate 84 and capscrews 86 and plate 74 has horizontal flanges 81 securedthereto which rest on table top 2 and is secured thereto by means ofbolts 82. Piston rod 88 extends from the right hand end of cylinder 83(FIG. 1) and has an upwardly extending link 90 secured thereto by meansof nut 91. Two parallel spaced apart horizontal rods 92 extend betweenand are fastened to plates 72 and 74. A clamp carrying block 94 isslidably mounted on rods 92 and is connected to link 90 by means of ahorizontal pull rod 96 slidably received in the plate 74 between rods92. The end of rod 96 remote from link 90 is connected to block 94 bypin 98. As best shown in FIG. the block 94 has a recess 100 forreceiving a bottom knurled gripping jaw 102. Spaced apart flanges 104 atthe upper end of block 94 receive a lug 106 of a clamping cover 108. Apin 110 passing through aligned holes in flanges 104 and lug 106pivotally connect cover 108 to block 94. The cover 108 has a top knurledgripping jaw 111 received in recess 112. When the jaws are closed theyform an opening in line with opening 62 for receiving cable C. Togglemechanism 114 mounted on block 94 moves clamping cover 108 downwardlyabout pivot pin 110 to clamp cable C in position.

In operation, with the clamping cover 108 open the end of a cable C ispassed into and through opening 62 from the right side (FIG. 1) and laidon gripping jaw 102. The cover 108 is then closed to firmly grip thecable C between jaws 102 and 111. Fluid is then delivered into thebottom of cylinder 32 thus raising plate 36 to move plates 40 and 44upwardly and compressing springs 58 and 60. This movement continuesuntil the blades have penetrated the jacket J to the proper depth andthe ground G and conductors S have been severed by blades 66 and 68.Fluid is then delivered into the left end (FIG. 1) of cylinder 83 topush its rod 88 away from the step cutter 4. This moves the clampingblock 94 in the same direction, thus pulling the ground G and conductorsS out of that portion of the jacket S to the left of blades 64. Theclamping cover 108 is then opened and the piston rods 34 and 88 returnedto their original position. The cable C is removed with its ends beingas shown in FIG. 6. The end of a second cable is then prepared in thesame manner; the insulation stripped from the conductor ends, connectorspositioned around the conductors and crimped thereto, the ends of theconductors insulated, and a new jacket placed about the joint tocomplete the splice. It will be seen that the cutters can be replaced byother cutters or the entire die block 38 easily removed and replaced bya block of a different design for use with other types of cables.

While one embodiment of my invention has been shown and described, itwill be apparent that other adaptations and modifications may be madewithout departing from the scope of the following claims.

I claim:

1. The method of cutting conductors of a multiconductor cable todifferent lengths and stripping a jacket from the end of the cable whichcomprises passing a straight end portion of said cable between multiplecutters spaced apart in the direction of the cable length, laying saidportion on a gripping means located inwardly from the end to be cut andstripped, closing said gripping means on the cable, bringing saidcutters together simultaneously to cut through said jacket at a locationbetween the end of the cable and the position where the cable is grippedand bringing other of said cutters together to cut through saidconductors at different distances between the end of the cable and theposition where said jacket is cut, and then moving said gripped cableaway from said cutters while the end portions of the conductors remainstraight and while the cutters are together to remove the jacket fromthe cable between the cut portion and the end of the cable.

1. The method of cutting conductors of a multi-conductor cable todifferent lengths and stripping a jacket from the end of the cable whichcomprises passing a straight end portion of said cable between multiplecutters spaced apart in the direction of the cable length, laying saidportion on a gripping means located inwardly from the end to be cut andstripped, closing said gripping means on the cable, bringing saidcutters together simultaneously to cut through said jacket at a locationbetween the end of the cable and the position where the cable is grippedand bringing other of said cutters together to cut through saidconductors at different distances between the end of the cable and theposition where said jacket is cut, and then moving saiD gripped cableaway from said cutters while the end portions of the conductors remainstraight and while the cutters are together to remove the jacket fromthe cable between the cut portion and the end of the cable.